As a widely utilized phenomenon, condensation heat transfer is deeply related to the efficiency of energy utilization in industry. In recent decades, the condensation of vapor mixture attracted extensive attention, since the possibility to achieve high performance of heat transfer. During the condensation of some binary vapor Marangoni condensation), a special phenomenon was discovered that the spontaneous movement of condensate drop occurred. It was observed that condensate drops moved from the low temperature region to the high temperature region on a heat transfer surface. Therefore, the surface tension gradient induced by the temperature gradient was considered as the driving force. However, another affecting factor on the spontaneous movement of condensate drops, the direction of vapor flow, was also discovered. In this study, the experimental study was performed, and the results showed that the condensate drops tended to move towards the inlet direction of vapor flow.
Keywords Marangoni condensation, Spontaneous drop movement, Waterâ€“ethanol vapor mixture, Surface tension